tree 53af4db451621e7ca5f9cd93db44c3c5782076c9
parent 3053b781465711fd05b88ab141b1f2b55a875516
author Pali Rohár <pali@kernel.org> 1652820328 +0200
committer Tom Rini <trini@konsulko.com> 1654266202 -0400

ubifs: Fix lockup/crash when reading files

Commit b1a14f8a1c2e ("UBIFS: Change ubifsload to not read beyond the
requested size") added optimization to do not read more bytes than it is
really needed. But this commit introduced incorrect handling of the hole at
the end of file. This logic cause U-Boot to crash or lockup when trying to
read from the ubifs filesystem.

When read_block() call returns -ENOENT error (not an error, but the hole)
then dn-> structure is not filled and contain garbage. So using of dn->size
for memcpy() argument cause that U-Boot tries to copy unspecified amount of
bytes from possible unmapped memory. Which randomly cause lockup of P2020
CPU.

Fix this issue by copying UBIFS_BLOCK_SIZE bytes from read buffer when
dn->size is not available. UBIFS_BLOCK_SIZE is the size of the buffer
itself and read_block() fills buffer by zeros when it returns -ENOENT.

This patch fixes ubifsload on P2020.

Fixes: b1a14f8a1c2e ("UBIFS: Change ubifsload to not read beyond the requested size")
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>